The 34-year-old actress donned a blunt blonde wig to truly look the part of Romy White while attended a couple of different A-list parties around Los Angeles on Friday.

Alba and her friend, Kelly Sawyer, rocked the shiny dresses worn by the lead characters during the movie's pivotal reunion scenes to George Clooney's Casamigos Tequila Halloween Party in Beverly Hills.

"@kellysawyer I invented post-its," Alba captioned an Instagram snap, referencing a famous line from the flick.

The pals were joined by Alba's husband, Cash Warren, who also got inspiration from a classic movie for his Halloween costume. The 36-year-old producer dressed up as Maverick from Top Gun for the soiree.

Jesse Grant/Getty Images

Later in the evening, Alba and Sawyer stopped by Jared Leto's house party, where they met up with the host, who was dressed as the Pope; killer cowgirl Gwen Stefani, who had also been at Clooney's bash; and another '90s-loving reveler, Derek Blasberg. The Vanity Fair writer played the part of Dionne from Clueless for the night, and he made sure to snap a photo with this nostalgic crew.

"THE 90'S ARE FRIGGIN' BACK!" Blasberg captioned the Instagram snap, posted on Saturday.

Jessica Alba arrives at The Metropolitan Museum of Art's Costume Institute benefit gala celebrating "China: Through the Looking Glass" on Monday, May 4, 2015, in New York. (Photo by Charles Sykes/Invision/AP)

LOS ANGELES, CA - AUGUST 14: Jessica Alba seen at LAX on August 14, 2014 in Los Angeles, California. (Photo by GVK/Bauer-Griffin/GC Images)

NEW YORK, NY - AUGUST 14: (EXCLUSIVE COVERAGE) Jessica Alba visits Sway in the Morning' with Sway Calloway on Eminem's Shade 45 at SiriusXM Studios on August 14, 2014 in New York City. (Photo by Robin Marchant/Getty Images)

NEW YORK, NY - AUGUST 13: Actress Jessica Alba visits 106 & Park at BET studio on August 13, 2014 in New York City. (Photo by Bennett Raglin/BET/Getty Images for BET)

NEW YORK, NY - AUGUST 12: Actress Jessica Alba is seen Soho on August 12, 2014 in New York City. (Photo by Raymond Hall/GC Images)

NEW YORK NY - AUGUST 05: Jessica Alba sighting on August 05, 2014 in New York City.
(Photo by Josiah Kamau/BuzzFoto/FilmMagic)

NEW YORK, NY - SEPTEMBER 29: Jessica Alba speaks onstage during An Honest Conversation with Jessica Alba and Christopher Gavigan on September 29, 2014 in New York City. (Photo by Neilson Barnard/Getty Images for AWXI)

NEW YORK, NY - SEPTEMBER 29: Jessica Alba is seen in New York City on September 29, 2014 in New York City. (Photo by Ignat/Bauer-Griffin/GC Images)

NEW YORK, NY - SEPTEMBER 27: Jessica Alba attends VIP Lounge at the 2014 Global Citizen Festival to end extreme poverty by 2030 in Central Park on September 27, 2014 in New York City. (Photo by Ilya S. Savenok/Getty Images for Global Citizen Festival)

NEW YORK, NY - SEPTEMBER 26: Jessica Alba is seen on September 26, 2014 in New York City. (Photo by David Krieger/Bauer-Griffin/GC Images)

NEW YORK, NY - SEPTEMBER 26: Actress Jessica Alba attends the Global Citizen Festival - The Action Summit 2014 on September 26, 2014 in New York City. (Photo by Cindy Ord/Getty Images)

LOS ANGELES, CA - SEPTEMBER 19: Jessica Alba is seen in Santa Monica on September 19, 2014 in Los Angeles, California. (Photo by Bauer-Griffin/GC Images)

NEW YORK NY - SEPTEMBER 13: Jessica Alba sighting on September 13, 2014 in New York City.
(Photo by Josiah Kamau/BuzzFoto/FilmMagic)

NEW YORK, NY - SEPTEMBER 10: Jessica Alba attends the unveiling of The Honest Company Ultra Clean Room at The Mount Sinai Hospital on September 10, 2014 in New York City. (Photo by Kevin Mazur/Getty Images for The Honest Company)

NEW YORK, NY - SEPTEMBER 09: Actress Jessica Alba is seen in Soho on September 9, 2014 in New York City. (Photo by Raymond Hall/GC Images)

HOLLYWOOD, CA - SEPTEMBER 05: JESSICA ALBA attend Stand Up To Cancer (SU2C), a program of the Entertainment Industry Foundation (EIF), staging its fourth biennial fundraising telecast at the at the Dolby Theatre on Friday September 5, 2014 (8:00-9:00 p.m., ET/PT) in Hollywood California. (Photo by Image Group LA/American Broadcasting Companies Inc via WireImage)

HOLLYWOOD, CA - AUGUST 19: Actress Jessica Alba arrives at the Los Angeles premiere of 'Sin City: A Dame To Kill For' at TCL Chinese Theatre on August 19, 2014 in Hollywood, California. (Photo by Axelle/Bauer-Griffin/FilmMagic)

HOLLYWOOD, CA - AUGUST 19: Actress Jessica Alba and Cash Warren arrive at the Los Angeles premiere of 'Sin City: A Dame To Kill For' at TCL Chinese Theatre on August 19, 2014 in Hollywood, California. (Photo by Axelle/Bauer-Griffin/FilmMagic)

Actress Jessica Alba attends the celebration for the TOMS for Target holiday partnership at The Book Bindery on Wednesday, Nov. 12, 2014 in Culver City, Calif. (Photo by Dan Steinberg/Invision/AP Images)